Electric terminal and coupling

ABSTRACT

An electric terminal for connecting a high limit switch in series with a pilot-burner-heated thermocouple and a safety control energizable thereby. It embodies a wafer-shaped insulator with contact portions of lead wires located on opposite sides of the insulator. The terminal fits in an internally threaded socket of a housing for an electromagnet forming part of the control and is held therein by a connector nut for receiving the thermocouple&#39;&#39;s lead terminals.

United States Patent Jayaram et a1.

[451 Apr. 4, 1972 [541 ELECTRIC TERMINAL AND COUPLING [72] lnventors: M. R. Jayaram, Long Beach; Nickolas J.

Sidarls, Cypress, both of Calif.

[ 73] Assignee: Honeywell Inc., Minneapolis, Minn.

[22] Filed: July 2, 1970 [21] Appl. No.: 52,037

[52] 11.8. CI. ..339/147 R, 136/235, 236/21 B, 339/176 T [51] lnt.Cl. V .,I-l0lv 1/10, l-lOlr 3/00 [58] Field of Search ..339/l74, 176 T, 214, 221,198 G, 339/198 G1, 198 1-1, 151 R; 137/66; 236/21 B;

[56] References Cited UNITED STATES PATENTS 3,467,893 9/1969 Jackson et al ..339/92 X 2,643,365 6/1953 Rose ..339/198 1-1 3,286,216 11/1966 Jackson et al.. .....339/89 C 3,426,316 2/1969 Olson ..339/l5l Primary Examiner-Marvin A. Champion Assistant Examiner-Lawrence J. Staab Attorney-Lamont B. Koontz and Alan M. Staubly [5 7] ABSTRACT An electric terminal for connecting a high limit switch in series with a pilot-burner-heated thermocouple and a safety control energizable thereby. 1t embodies a wafer-shaped insulator with contact portions of lead wires located on opposite sides of the insulator. The terminal fits in an internally threaded socket of a housing for an electromagnet forming part of the control and is held therein by a connector nut for receiving the thermocouple s lead terminals.

4 Claims, 6 Drawing Figures PATENTEDAPR 41912 3,654,591

SHEEI 1 BF 2 INVENTORS M R JAYARAM By NICKOLAS J. SIDARIS MWXM A TTOR/VE Y.

PATENTEDAPR M972 3.654.591

SHEET 2 OF 2 INVIZN'IURS M. R. JAYARAM NICKOLAS J. SIDARIS MQmM ATTORNE).

ELECTRIC TERMINAL AND COUPLING The invention is directed to an improved arrangement for connecting the leads of a high switch in series with a pilotbumer-heated thermocouple and an electromagnet that controls a safety valve or switch used for controlling the flow of gas to a gas burner. The system is generally well known in the gas appliance art, and numerous arrangements have been commercially used for connecting the pilot-burner-heated thermocouple to an electromagnet controlling a gas valve or the like. These have been generally unsatisfactory to the extent that they were difficult to assemble and, therefore, were more expensive than they needed to be.

FIG. 1 of the drawing is a plan view of a wafer-shaped insulator used to retain leads and contact members connected to a safety or high limit switch;

' FIG. 2 is a side view of the insulator of FIG. 1;

FIG. 3 is a cross-sectional view of the insulator, with the lead terminals therein and located in a housing for an electromagnet power unit, taken along line 3-3 of FIG. 1.

FIG. 4 is a cross-sectional view of a modification of the invention;

FIG. 5 is a plan view of the wafer-shaped insulator of FIG. 4; and

FIG. 6 is a cross-sectional view of the insulator taken along line 6-6 of FIG. 5.

In one embodiment of the invention, as illustrated in FIGS. 1-3, the insulator 1 1 is of round shape and has a radial projection 1 In at one point of its periphery. At the center of the insulator, a recess 12 communicates with a groove 13 that extends to the outer end of the extension 11a, in one surface of the insulator; while on the other side of the insulator, a stepped recess 14a-14b cooperates with recess 12 to form a layer 15 of insulation between the bottoms of the two recesses with a contact supporting or bearing surface on each side. The recess 14a-l4 communicates with a groove 16 in the same surface of the insulator but on the other side of a radial line from the center of the insulator to the center of the projection 11a from the groove 13, with the groove 16 also terminating at the outer end of the projection 11a. An annular rib 17 is formed in the bottom of the recess 14a for a purpose to be described hereinafter. Surrounding and slightly spaced from the recess 12, is a C-shaped or substantially annular rib 18 to provide centering and extra protection against transverse movement of a thermocouple lead terminal when positioned therein.

A lead 19 from a conventional high limit switch (not shown) is suitably connected at 20 to a tangential extension 21a of a bshaped electrical contact member 21, which is anchored in the insulator by an interference fit in the generally round recess 12. A second lead 22 is similarly connected to a similar contact member 23, which is similarly held in the recess 14a. The lead 19 rests in groove 13 while the lead 22 rests in groove 16.

The terminal assembly just described fits in a recess 24 that is formed in a housing 25 for an electromagnet type of power unit 26. It is located between the end wall 27 of the electromagnet power unit and a ring-shaped connector nut 28 screw-threaded into the open end of the housing 25. The housing has a slot 25a extending from its outer end to a point inwardly of the outer surface of the end wall 27, to accommodate the projection 11a of the insulator. The contact member 14a engages the rounded end 30b of a terminal 30a which, in turn, is connected to one end of a coil 30. The other end of the coil 30 is grounded to the end wall 27. The connector nut 28 receives the head of inner lead 31 of a thermocouple (not shown) and the externally threaded terminal nut 32 which bears against a shoulder of outer lead 33 to form an electrical connection between the outer lead 33 and the clamping nut 28. The nut is electrically connected through housing 25, an aluminum or brass washer 34 and wall 27 to coil 30. The other end of the coil 30 connects to the inner lead unit 26 and the housin 25. When the thermocouple leads 31 and 33 are inserted int e connector nut 28, and the connector 32 is tightly screwed into the connector nut 28, the head 31a forces the contact member 21 against the partition wall 15 with sufficient force as to bend the contact 14a over the surface of the head 30b to make a good electrical contact therebetween.

The assembly just described is adapted to operate in a conventional manner; that is, when a pilot flame is present for heating a thermocouple connected to the leads 31 and 33, current will be supplied through the leads 19 and 22 to the normally closed safety switch and to the coil 30 of the electromagnet. As the electromagnet is part of a conventional and commercially available safety device, such as a gas valve or switch of the manually resettable type, there is no need to further define the functioning of the apparatus.

The modification of the invention illustrated in FIGS. 4, 5 and 6 is generally similar to the one of FIGS. 1-3 but wherein each of the bared ends of the lead wires is longer and may or may not be flattened intermediate the ends at 121 and 123, respectively, thereof and is positioned coaxially of the assembly. The wire ends extend into diametrically extending holes 1 l3 and 116 intersecting recesses l 12 and 114a, respectively, in each surface of the insulator 111. Other minor differences lie in a flat terminal head b and a heat staking of the insulator 11 about the bared lead wires, adjacent contact portions 121 and 123 and the adjoining insulation on lead wires 119 and 122. If desired, grooves 112 and 114a may be provided to aid in centering and holding the wire portions 121 and 123, respectively.

The functioning of the assembly illustrated in FIGS. 4, S and 6 is the same as that of FIGS. l-3. Obviously, the washer 134 of FIGS. 4-6 could be made out of insulating material that possibly would provide a better gas seal than the metal washer 34 of FIGS. l-3. Also, the insulator 11 could be of a smaller diameter and located in a sleeve similar to 129 to provide thrust and an electrical connection between wall 27 and nut 28.

The embodiments of the invention in which an exclusive property or right is claimed are defined as follows:

1. A control device comprising a housing with a stepped opening therein, an electric power control unit in said opening and having an external shoulder thereon resting on a step of said opening, an external electric terminal on said power unit, insulator means located in said opening and having a first terminal on one side of said insulator means in engagement with said electric terminal and a second terminal on the other side of said insulator means, insulated leads extending from said first and second terminals and from said insulator means, a connector closure secured in the outer end of said opening and at least partially holding said power unit and insulator means in said housing and having a bore therein in alignment with said second terminal for receiving and holding the terminal means of a thermocouple, and a sleeve, having a transverse opening therethrough and through which said leads extend, lying between said insulator means and the side walls of said stepped opening and extending from said closure to said power unit.

2. A control device as defined in claim 1 wherein said housing has a transverse opening therein extending from said stepped opening and through which said leads extend.

3. A control device as defined in claim 2 wherein said insulator means has a projection which extends into said transverse opening.

4. A control device as defined in claim 1 wherein said transverse opening in said housing and sleeve extends to the outer ends thereof. 

1. A control device comprising a housing with a stepped opening therein, an electric power control unit in said opening and having an external shoulder thereon resting on a step of said opening, an external electric terminal on said power unit, insulator means located in said opening and having a first terminal on one Side of said insulator means in engagement with said electric terminal and a second terminal on the other side of said insulator means, insulated leads extending from said first and second terminals and from said insulator means, a connector closure secured in the outer end of said opening and at least partially holding said power unit and insulator means in said housing and having a bore therein in alignment with said second terminal for receiving and holding the terminal means of a thermocouple, and a sleeve, having a transverse opening therethrough and through which said leads extend, lying between said insulator means and the side walls of said stepped opening and extending from said closure to said power unit.
 2. A control device as defined in claim 1 wherein said housing has a transverse opening therein extending from said stepped opening and through which said leads extend.
 3. A control device as defined in claim 2 wherein said insulator means has a projection which extends into said transverse opening.
 4. A control device as defined in claim 1 wherein said transverse opening in said housing and sleeve extends to the outer ends thereof. 